FLiNaK熔盐浸渗对2D C/C复合材料力学性能的影响

Impregnating molten LiF-NaF-KF salt (46.5%-11.5%-42.0%,mole fraction, FLiNaK) into a 2D woven C/C composite was performed at 650℃ under different pressure. The mass gain, the change of density and mechanical properties of the 2D woven C/C composite after FLiNaK salt impregnation were measured. The FLiNaK salt distribution in the 2D woven C/C composite was observed by X-ray CT and SEM. The results show that the mass gain of the 2D woven C/C composite increased with the increasing impregnation pressure. FLiNaK salt distributed within open pores of the composite and fissures of fiber bundles and interlaminar fractures. The compressive strength and flexural strength of the 2D woven C/C composite increased with the increasing impregnation pressure. The coupling effect of densification induced by FLiNaK salt impregnation and residual stress formed in 2D woven C/C composite could be benefitial to the mechanical property of the C/C composite.